• Title/Summary/Keyword: density index

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Optical simulation of micro-pyramid arrays for the applications in the field of backlight unit of LCD

  • Lee, Ji-Young;Kim, Young-Jin;Nahm, Kie-Bong;Ko, Jae-Hyeon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1343-1346
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    • 2006
  • Optical performances of micro-pyramid arrays were simulated by ray tracing technique for the application of backlight unit of LCD. The angular distribution of the luminance and the on-axis luminance gain depended on the apex angle, the refractive index, and the density of micro-pyramids. The on-axis luminance reached a maximum when the apex angle was $90^{\circ}$. It also increased as the density and the refractive index of micro-pyramids increased. The present result showed that highly-efficient optical sheet might become realized by adopting micropyramid array and corresponding development of manufacturing processes.

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The Analysis of Ultrasonography on Gastrocnemius Medialis of Patient with Stroke (뇌졸중환자 내측 비복근의 초음파 영상 분석)

  • Seo, Sam-Ki
    • The Journal of Korean Physical Therapy
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    • v.19 no.2
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    • pp.11-19
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    • 2007
  • Purpose: The purpose of this study were to analyze ultrasonography on both sides of gastrocnemius medialis of stroke patient. Methods: In fourteen subjects with stroke, the gastrocnemius medialis(GM) muscle were scanned with ultrasonography at the muscle belly at rest at ankle angles of 0 degree (neutral position) and it were measured with ultrasonography on both sides of the leg. Muscle architecture (thickness, pennation angle, fascicle length, density, white area index) was examined using real-time B-mode ultrasonography with 7.5MHz linear-array prob. Results: Thickness of non-paratic side was significantly thicker than paratic side. Pennation angle of non-paratic side was significantly larger than paratic side. Fascicle length of non-para tic side was significantly smaller than paratic side. Density of non-paratic side was significantly smaller than paratic side. White area index of non-paranc side was significantly smaller than paratic side. Conclusion: This study showed that stroke have influenced on mechanical properties and quality properties of skeletal muscle architecture.

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Detection of Laver Aquaculture Site of Using Multi-Spectral Remotely Sensed Data (다중분광 위성자료를 이용한 김 양식어장 탐지)

  • Jeong, Jongchul
    • Journal of Environmental Impact Assessment
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    • v.14 no.3
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    • pp.127-134
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    • 2005
  • Recently, aquaculture farm sites have been increased with demand of the expensive fish species and sea food like as seaweed, laver and oyster. Therefore coastal water quality have been deteriorated by organic contamination from marine aquaculture farm sites. For protecting of coastal environment, we need to control the location of aquaculture sites. The purpose of this study is to detect the laver aquaculture sites using multispectral remotely sensed data with autodetection algorithm. In order to detect the aquaculture sites, density slice and contour and vegetation index methods were applied with SPOT and IKONOS data of Shinan area. The marine aquaculture farm sites were extracted by density slice and contour methods with one band digital number(DN) carrying 65% accuracy. However, vegetation index algorithm carried out 75% accuracy using near-infra red and red bands. Extraction of the laver aquaculture site using remotely sensed data will provide the efficient digital map for coastal water management strategies and red tide GIS management system.

Risk Factors of Osteopenia among Korean Middle-aged Women (중년여성의 골감소증 위험요인)

  • Kim, Gwang Suk;Lee, Yoon Ju;You, Mi-Ae
    • Journal of Home Health Care Nursing
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    • v.20 no.2
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    • pp.133-140
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    • 2013
  • Purpose: This study examined the demographic and lifestyle differences between women with osteopenia and those with normal bone mineral density (BMD) to identify risk factors for osteopenia. Method: Participants comprised 381 women age 40-64 years. Data were collected using surveys, BMD measures, and anthropometric parameters. Results: Prevalence of osteopenia was 29.1%; significant differences in age group, job, age at menarche, age at menopause, and body mass index were found between women with osteopenia and those with normal BMD. Logistic regression analysis indicated that advanced age, unemployment, lower body mass index, and lack of exercise in women were significantly associated with osteopenia. Conclusion: This study suggests the need for strategies to improve bone health and continuous cohort studies to identify risk factors.

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Studies on AlF3-(Mg+Sr+Ba)F2-P2O5 Glasses I. Glass Forming Ranges of Fluorophosphate System and Its Various Properties (AlF3-(Mg+Sr+Ba)F2-P2O5계 유리에 관한 연구 I. 유리화 범위와 특성)

  • 김정은;이종근
    • Journal of the Korean Ceramic Society
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    • v.24 no.2
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    • pp.117-122
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    • 1987
  • Glass forming ranges in the AlF3-(Mg+Sr+Ba)F2-P2O5 system are studied and ultraviolet transmission, infrared transmission, coefficient of refractive index, thermal expansion coefficient, density and chemical durability of the glasses are determined. Glass forming range is restricted MgF2 0-10wt%, SrF2 10-50wt%, BaF2 10-40wt% in this system. While BaF2 is substituted by SrF2, density and refractive index are decreased, micro hardness and thermal expansion coefficient are increased according to the increasing of SrF2 at fixed MgF2 contents. These samples represent high transmittance(93%) from 400nm to 3800nm and chemical durability of these samples show less than 0.3mg/$\textrm{cm}^2$$.$hy by weightloss.

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Density-Order Index Rule for Stock Location in a Distribution Warehouse

  • Hwang, Hark;Cha, Chun-Nam
    • Journal of Korean Institute of Industrial Engineers
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    • v.15 no.1
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    • pp.41-50
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    • 1989
  • This paper deals with the problem of space allocation of items within a warehouse. Recognizing the importance of weights associated with material handling, mathematical models are developed for two cases, out-and-back selection and storage retrieval interleaving. It is proved that the density order index rule we proposed generates an optimal solution for the first model. An example problem solved with the pairwise interchange method indicates that the rule is also fairly efficient for the second model. The proposed rule is compared with other assignment rules of warehouse space such as COI rule, space and popularity.

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Flame Retardancy and Mechanical Property of Recycled Polyolefinic Plastic Composites with Hybrid fillers (폴리올레핀계 폐플라스틱/복합filler 성형체의 난연성 및 기계적 물성 연구)

  • 강영구;송종혁
    • Journal of the Korean Society of Safety
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    • v.18 no.2
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    • pp.56-63
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    • 2003
  • Flame retardancy and mechanical properties of recycled polyolefinic plastics/inorganic filler composite systems were investigated by using several inorganic flame retardants such as magnesium hydroxide and slag powder generated electro arc furnace Compatibilizer user each maleic anhydride functionalized polyethylene (PE-g-MAH) and polypropylene(PP-g-MAH) or used mixture of these. The effect of polymeric compatibilizers on the properties of composites was studied by tensile and impact test, differential scanning calorimetry, in the changed fracture mechanism. The improved adhesion was particularly reflected in the mechanical properties. The flame retardancy of composites was examined by measuring limiting oxygen index(LOI, ASTM D2863), smoke density(ASTM D2843) and vertical burning test(UL94). Regarding the flame retardant effect, the EAF slag powder is behaving as synergists as they are only active in the presence of magnesium hydroxide.

Simplified Machine Diagnosis Techniques by Impact Vibration using n-th Moment of Absolute Deterioration Factor

  • Takeyasu, Kazuhiro;Amemiya, Takashi;Tanaka, Jumpei;Masuda, Shiro
    • Industrial Engineering and Management Systems
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    • v.4 no.1
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    • pp.68-74
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    • 2005
  • Among many dimensional and dimensionless amplitude parameters, kurtosis (4-th normalized moment of probability density function) is generally regarded as a sensitive good parameter for machine diagnosis. However, higher order moment may be supposed to be much more sensitive. Bicoherence is an absolute deterioration factor whose range is 1 to 0. The theoretical value of n-th moment divided by n-th moment calculated by measured data would behave in the same way. We propose a simplified calculation method for an absolute index of n-th moment and name this as simplified absolute index of n-th moment. Some favorable results are obtained.

Survey on Food Consumption Patterns and Nutrient Intakes of College Students by Body Mass Index (체질량지수에 따른 남녀대학생들의 식품 소비경향과 영양소 섭취실태에 관한 연구)

  • Choi, Ji-Hyun;Wang, Soo-Kyung
    • Journal of the Korean Society of Food Culture
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    • v.11 no.5
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    • pp.689-698
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    • 1996
  • This study was designed to investigate food consumption patterns and nutrient intakes of college students, divided into subgroups of normal weight men (no.=140), normal weight women (no.=101), and underweight women (no.=155) by body mass index. Frequency of food eaten, nutrient intakes from each meal, percentages of RDAs, and nutrient densities were analyzed using 24-hour recall records. It was very interesting in these results as follows. Normal weight men ate on the whole more frequently than other groups. Underweight women had higher intakes of nutrient than did normal weight women. However normal weight women consumed food of greater nutrient density than did other college students. Consequently, it is desirable to suggest nutrient density of food than learn RDAs for adequate diet in nutritional education programs.

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Fabrication of La2O3-TiO2-SiO2 System Glass Derived from a Sol-Gel Process

  • Iwasaki, Mitsunobu;Masaki, Hitoshi;Ito, Seishiro;Park, Won-Kyu
    • Journal of the Korean Ceramic Society
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    • v.44 no.3 s.298
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    • pp.137-141
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    • 2007
  • $La_{2}O_{3}-TiO_{2}-SiO_{2}$ glass, a type that could not obtained so far by the conventional melting method, was prepared successfully using a sol gel process. Glass derived with the sol-gel process has compositions of $5La_{2}O_{3}-5TiO_{2}-90SiO_{2},\;5La_{2}O_{3}-10TiO_{2}-85SiO_{2}$, and $5La_{2}O_{3}-20TiO_{2}75SiO_{2}$. The UV-visible absorption edge of all glass compositions was below 400 nm. The measured density is in the range of 2.55-2.89, and was nearly identical to the calculated density and the refractive index of the glasses derived from the sol-gel ranges from 1.545 to 1.645. The molar additive coefficient of $TiO_{2}$ measured in this ternary system is lower than the calculated value, while the value of $La_{2}O_{3}$ is higher.